Once again, the Slooh Space Camera team will host a live webcast of an asteroid flyby of Earth. This one might be a bit more intriguing than others, if only because of the connotation this asteroid has. Asteroid Apophis a near-Earth asteroid with an estimated diameter of almost three football fields (270m), is making its closest approach to us this year — but it will still be quite distant, at about 14 million km – but this is close enough for astronomers to study the space rock and assess its future risk.
On Wednesday, January 9th, Slooh.com, will start the webcast at 4 p.m. PST / 7 p.m. EST / 00:00 UTC (1/10) — International times here — accompanied by real-time discussions with Slooh President Patrick Paolucci, Slooh Outreach Coordinator and Engineer Paul Cox, and Documentary Filmmaker Duncan Copp.
Composite-color 3D image of Cornelia crater on Vesta (NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)
Ever since arriving at Vesta in July 2011, NASA’s Dawn spacecraft has been capturing high-resolution images of the protoplanet’s surface, revealing a surprisingly varied and complex terrain covered in ridges, hills, grooves and, of course, craters of many different sizes and ages. Many of Vesta’s largest craters exhibit strange dark stains and splotches within and around them, some literally darker than coal. These stains were a puzzle to scientists when they were first seen, but the latest research now confirms that they may actually be the remains of the ancient impacts that caused them: dark deposits left by the myriad of carbon-rich objects that struck Vesta over the past four-and-a-half billion years.
Even though Vesta had a completely molten surface 4.5 billion years ago it’s believed that its crust likely solidified within a few million years, making the 530-km (329-mile) -wide world a literal time capsule for events taking place in the inner Solar System since then… one reason why Vesta was chosen as a target for the Dawn mission.
Using data acquired by Dawn during its year in orbit around Vesta, a team led by researchers from Germany’s Max Planck Institute for Solar System Research and the University of North Dakota investigated the dark material seen lining the edges of large impact basins located on the protoplanet’s southern hemisphere. What they determined was that much of the material was delivered during an initial large, low-velocity impact event 2–3 billion years ago that created the largest basin — Veneneia — and was then partially covered by a later impact that created the smaller basin that’s nearly centered on Vesta’s southern pole — Rheasilva.
“The evidence suggests that the dark material on Vesta is rich in carbonaceous material and was brought there by collisions with smaller asteroids.”
– Vishnu Reddy, lead author, Max Planck Institute for Solar System Research and the University of North Dakota
Dawn framing camera images of dark material on Vesta. (NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)
Subsequent smaller asteroid impacts over the millennia likely brought more carbonaceous material to Vesta’s surface, both delivering it as well as revealing any that may have existed beneath brighter surfaces.
The dark, carbon-rich material observed on Vesta by Dawn also seems to match up with similarly dark clasts found in meteorites that have landed on Earth which are thought to have originated from Vesta.
“Our analysis of the dark material on Vesta and comparisons with laboratory studies of HED meteorites for the first time proves directly that these meteorites are fragments from Vesta,” said Lucille Le Corre from the Max Planck Institute for Solar System Research, another lead author of the study.
If evidence of such collisions between worlds can be found on Vesta, it’s likely that similar events were occurring all across the inner solar system during its early days, providing a clue as to how carbon-rich organic material was delivered to Earth — and possibly Mars as well. Such material — the dark stains we see today lining Vesta’s craters — would have helped form the very building blocks of life on our planet.
The team’s findings were published in the November/December issue of the journal Icarus.
Read more on the Max Planck Institute’s news page here, and on the NASA release here. Learn more about the Dawn mission in the video below, narrated by Leonard Nimoy.
NASA has compiled the radar images taken of Asteroid Toutatis during its flyby of Earth this week to create a short movie, which shows the asteroid slowly tumbling. The 64-frame movie was generated from data gathered on December 12 and 13, 2012 by NASA’s 70-meter Goldstone Deep Space Network antenna in Goldstone, California.
NASA provides more information about the video and (4179) Toutatis:
On Dec. 12, the day of its closest approach to Earth, Toutatis was about 18 lunar distances, 4.3 million miles (6.9 million kilometers) from Earth. On Dec. 13, the asteroid was about 4.4 million miles (7 million kilometers), or about 18.2 lunar distances.
The radar data images of asteroid Toutatis indicate that it is an elongated, irregularly shaped object with ridges and perhaps craters. Along with shape detail, scientists are also seeing some interesting bright glints that could be surface boulders. Toutatis has a very slow, tumbling rotational state. The asteroid rotates about its long axis every 5.4 days and precesses (changes the orientation of its rotational axis) like a wobbling, badly thrown football, every 7.4 days.
The orbit of Toutatis is well understood. The next time Toutatis will approach at least this close to Earth is in November of 2069, when the asteroid will safely fly by at about 7.7 lunar distances, or 1.8 million miles (3 million kilometers). An analysis indicates there is zero possibility of an Earth impact over the entire interval over which its motion can be accurately computed, which is about the next four centuries.
This radar data imagery will help scientists improve their understanding of the asteroid’s spin state, which will also help them understand its interior.
The resolution in the image frames is 12 feet (3.75 meters) per pixel.
Goldstone delay-Doppler radar images of Toutatis from December 11, 2012. Credit: NASA
While Asteroid 4179 Toutatis was never a threat to hit Earth during its quite-distant pass on Dec. 11-12, astronomers were keeping their instruments and eyes on this space rock to learn more about it, as well as learning more about the early solar system. Even at closest approach, 4179 Toutatis was 7 million km away or 18 times farther than the Moon. But that is close enough for radar imaging by NASA’s Goldstone Observatory, which has recently upgraded to a new digital imaging system, as well as optical imaging by other astronomers. Already, there are some preliminary findings from this 4.5-kilometer- long (3-mile-long) asteroid’s flyby.
“Toutatis appears to have a complicated internal structure,” said radar team member Michael Busch of the National Radio Astronomy Observatory. “Our radar measurements are consistent with the asteroid’s little lobe being ~15% denser than the big lobe; and they indicate 20% to 30% over-dense cores inside the two lobes.”
NASA says this raises the interesting possibility that asteroid Toutatis is actually a mash up of smaller space rocks. “Toutatis could be re-accumulated debris from an asteroid-asteroid collision in the main belt,” Busch said. The new observations will help test this idea.
Here are more images and video from Toutastis’ pass:
Adam Block from the Mount Lemmon SkyCenter/University of Arizona captured this footage:
Astronomers are getting to know this asteroid, as it passes by Earth’s orbit every 4 years. It is one of the largest known potentially hazardous asteroids (PHAs), and its orbit is inclined less than half-a-degree from Earth’s. No other kilometer-sized PHA moves around the Sun in an orbit so nearly coplanar with our own. This makes it an important target for radar studies.
Image from the ITelescope network (Nerpio, Spain) on 2012, Dec. 11.9, through a 0.15-m f/7.3 refractor + CCD. Credit: Ernesto Guido and Nick Howes/ Remanzacco Observatory.
And this was a fairly close pass for Toutatis: The next time Toutatis will approach at least this close to Earth is in November of 2069
when the asteroid will fly by at a distance of only 0.0198 AU (7.7 lunar distances).
NASA’s Goldstone radar in the Mojave Desert has been “pinging” the space rock every day starting on December 4, and will continue until the 22nd. The echoes highlight the asteroid’s topography and improve the precision with which researchers know the asteroid’s orbit.
Additionally, the Chinese Chang’e 2 spacecraft will be observing Toutatis tomorrow, on December 13, 2012 Chang’e 2 was originally launched to study the Moon but after completing its mission, Chang’e 2 departed from the L2 point in April 2012 to align itself to make a flyby of 4179 Toutatis, expected to take place at approximately 08:27 UTC on December 13.
“We already know that Toutatis will not hit Earth for hundreds of years,” said Lance Benner of NASA’s Near Earth Object Program.. “These new observations will allow us to predict the asteroid’s trajectory even farther into the future.”
Animation from Ernesto Guido and Nick Howes of 40 consecutive 10-second exposures. Credit: Ernesto Guido and Nick Howes/ Remanzacco Observatory.
NASA says the asteroid is already remarkable for the way that it spins. Unlike planets and the vast majority of asteroids, which rotate in an orderly fashion around a single axis, Toutatis travels through space “tumbling like a badly thrown football,” as Benner describes it. One of the goals of the radar observations is to learn more about the asteroid’s peculiar spin state and how it changes in response to tidal forces from the Sun and Earth.
Here’s an animation of Asteroid Toutatis compiled the live broadcast from the Slooh space camera team:
Goldstone delay-Doppler radar images of Toutatis from December 11, 2012. Credit: NASA
Image of Asteroid 2012 XE54 taken with the the H06 ITelescope network near Mayhill, New Mexico on December 11, 2012, through a 0.25-m f/3.4 reflector + CCD. Credit: Ernesto Guido & Nick Howes, Remanzacco Observatory.
A newly discovered small asteroid named 2012 XE54 passed harmlessly by Earth early today and as predicted it was eclipsed by Earth’s shadow, causing its light to “wink out” for a short time, about 40 minutes.
Above is an image of the asteroid from Ernesto Guido and Nick Howes using a 0.25-m f/3.4 reflector + CCD with the ITelescope facility near Mayhill, New Mexico. It is a single 60-second exposure, “taken with the asteroid at magnitude ~13.2 and moving at ~630 “/min. The asteroid is trailed in the image due to its fast speed. At the moment of the close approach 2012 XE54 will move at ~ 720″/min… North is up, East is to the left,” wrote Guido and Howes on the Remanzacco Observatory website.
Below is an animation showing the movement of 2012 XE54, using three consecutive 60-second exposures. This asteroid was zipping right along at a fast pace, at a distance from Earth of about 226,000 km (141,000 miles) or about .6 lunar distances.
Pasquale Tricarico of the Planetary Science Institute had predicted that the asteroid would pass through the Earth’s shadow, creating an asteroid eclipse, a rather rare event that is similar to an eclipse of the full Moon by Earth’s shadow. At 01:22 UTC on December 11 the eclipse began, and it left Earth’s shadow at 02:00 UTC. Those watching the asteroid noted that the asteroid “disappeared” from its track, and then reappeared after leaving Earth’s shadow.
“In two images taken at 01:30:16 and 01:31:18, 60sec exposure, 2012 XE54 appeared as a very faint and long track, then… nothing. In the following images there is no visible track. Wonderful!” wrote Elia Cozzi from the New Millennium Observatory, posting in the mpml asteroid research group message board.
While we don’t have images to share of that event, as Guido and Howes mentioned, Peter Birtwhistle produced a lightcurve (see graph below) of the eclipse:
Tricarico wrote that the first known case of an asteroid being eclipsed by Earth’s shadow was “Asteroid 2008 TC3 which was totally eclipsed just one hour before entering Earth’s atmosphere over Sudan in 2008, and asteroid 2012 KT42 experiencing both an eclipse and a transit during the same Earth flyby in 2012.”
Guido and Howes also mentioned that their work last night was “in memory of our dear friend & colleague Giovanni Sostero.”
Four computer generated views of Asteroid Toutatis based on Goldstone radar imagery. Via NASA
A newly discovered small asteroid named 2012 XE54 and a long-studied giant space rock named Toutatis will buzz past Earth during the next 24 hours, and astronomers are already watching the skies. While there is no danger of either hitting Earth, scientists have much to learn from both. Asteroid 2012 XE54 was discovered over the weekend on December 9 and it will safely pass between the Earth and the Moon’s orbit at a distance of about 226,000 km (141,000 miles) or about .6 lunar distances. Closest approach will be just a few hours after this article was posted, at 10:10 UTC on Dec. 11. But already an interesting event has already happened with this 28-meter-wide asteroid: it was eclipsed by Earth’s shadow. This is quite a rare event, and was visible to astronomers.
This animation shows the Sun and the Earth as observed from the asteroid 2012 XE54. If this eclipse occurs, the asteroid will be in Earth’s shadow. Animation via Pasquale Tricarico
Pasquale Tricarico of the Planetary Science Institute had predicted that the asteroid would pass through the Earth’s shadow, creating an asteroid eclipse, an event that is similar to an eclipse of the full Moon by Earth’s shadow. At 01:22 UTC on December 11 the eclipse began, and it left Earth’s shadow at 02:00 UTC. Those watching the asteroid noted that the asteroid “disappeared” from its track, and then reappeared after leaving Earth’s shadow.
“In two images taken at 01:30:16 and 01:31:18, 60sec exposure, 2012 XE54 appeared as a very faint and long track, then… nothing. In the following images there is no visible track. Wonderful!” wrote Elia Cozzi from the New Millennium Observatory, posting in the mpml asteroid research group message board.
We hope to have images of the event when they become available.
4179 Toutatis, with a shape that has been described as a “malformed potato” will pass at a large distance of 6.9 million kilometers (4.3 million miles) away from Earth, or more than 18 times the distance from the Earth to the Moon.
It is a biggie, though at 4.46 kilometers (2.7 miles) long and 2.4 kilometers (1.5 miles) wide, and is considered a potentially hazardous asteroid because it makes repeated passes by the Earth, about every four years. In comparison, the asteroid that is thought to have destroyed the dinosaurs was approximately 10 km (6 miles) wide.
It’s closest pass will be covered by the Slooh Space Camera on Tuesday, December 11th, with several live shows on Slooh.com, free to the public, starting at 20:00 UTC (12 PM PST / 3 PM EST, find international times here — accompanied by real-time discussions with Slooh President, Patrick Paolucci, and Astronomy Magazine columnist, Bob Berman.
At its maximum brightness, Toutatis might be barely visible through binoculars, but should be very bright through Slooh telescopes at its being tracked.
“We will be tracking Asteroid Toutatis live from two observatory locations – Canary Islands, off the coast of Africa and Arizona,” said Patrick Paolucci, President at Slooh.
Astronomers are interested in this returning asteroid to try and figure out what the asteroid is made of. Also by refining a model of the asteroid’s rotation, they’ll get a better idea of its composition, thereby gaining a greater understanding of the early solar system.
Lance Benner from JPL said that this asteroid is tumbling slowly, but with a complex motion.
“It’s a very peculiar rotation state,” Benner said. “It rotates very slowly and it tumbles in a manner somewhat similar to the way a football tumbles if you screw up a long pass.”
The Geminid Meteor Shower is the grand finale of astronomical events in 2012 and is usually the most reliable and prolific of the annual meteor showers.
This year we are in for a special treat as the Moon will be absent when the Geminids are at their peak on the evening of the 12th/ 13th of December. This means that the sky should be at its darkest when the shower is expected, and many more of the fainter meteors may be seen.
The Geminid meteor shower is expected to yield in excess of 50 meteors (shooting stars) per hour at peak for those with clear skies, the meteors it produces are usually bright with long persistent trains. If observing opportunities aren’t favorable or possible on the 12th/ 13th, meteor watchers can usually see high meteor activity a day or so either side of the peak.
As well as being the grand finale of 2012, the Geminids are special in another way. Unlike the majority of all the other annual meteor showers the Geminids are thought to be from an object known as 3200 Phaethon – an asteroid not a comet.
To celebrate this long anticipated event, there will be the Geminid Meteorwatch and anyone with an interest in the night sky can join in on Twitter, Facebook and Google+. The event will be an excellent opportunity to learn, share information, experiences, images and more. Whatever your level of interest, wherever you are on the planet Meteorwatch will run for approximately four days. All you need to do is follow along using the #meteorwatch hashtag.
As well as the wealth of information exchanged and shared on Twitter and the other social media outlets, there are helpful guides and information available on Meteorwatch.org so you can get the most out of your #meteorwatch.
To get the ball rolling there is a Hollywood style trailer for the event, purely as a bit of fun and for people of all walks of life to feel inspired and to go outside and look up. You don’t need a telescope or anything, just your eyes and a little bit of patience to see a Geminid meteor.
Radar images of asteroid 2007 PA8 acquired on October 28, 29 and 30. (NASA/JPL-Caltech/Gemini)
Take a good look at asteroid 2007 PA8 — over the past week it was making its closest pass of Earth for the next 200 years… and NASA’s 230-foot (70-meter) -wide Deep Space Network antenna at Goldstone, California snapped its picture as it went by.
All right, maybe no “pictures” were “snapped”… 2007 PA8 is a small, dark body that only came within four million miles (6.5 million kilometers) today, Nov. 5 (0.043 AU, or 17 times the distance from Earth to the Moon). But the radar capabilities of the Deep Space Network antenna in California’s Mojave Desert can bounce radar off even the darkest asteroids, obtaining data that can be used to create a detailed portrait.
In the image above, a composite of radar data acquired on October 28, 29 and 30, we can see the irregular shape of 2007 PA8 as it rotates slowly — only once every 3-4 days. The perspective is looking “down” at the 1-mile (1.6-km) -wide asteroid’s north pole, showing ridges and perhaps even some craters.
Although classified as a Potentially Hazardous Asteroid (PHA) by the IAU’s Minor Planet Center the trajectory of 2007 PA8 is well understood. It is not expected to pose any impact threat to Earth in the near or foreseeable future.
2007 PA8 was discovered by LINEAR on August 9, 2007.
An artist’s impression of the different configurations of asteroid belts that could occur. Image credit: NASA/ESA/A. Feild, STScI
Sure, asteroids can be planetary annihilators, scouring the surface of a world with fire and molten rock. But asteroids might also help seed a planet with the right ingredients to set up the conditions for life, and give that life encouragement to evolve more complex survival strategies.
As with all things, it’s just about balance. Too many asteroids, and you’ve got an unrelenting cosmic shooting gallery, raining fiery death from above. Too few asteroids, and complex life might not get the raw material it needs to get rolling. Life never gets that opportunity to really shake things up and evolve into more complex forms.
This conclusion comes from Rebecca Martin, a NASA Sagan Fellow from the University of Colorado in Boulder and Mario Livio of the Space Telescope Science Institute in Baltimore, Md. The researchers created a series of theoretical models based on observations of debris disks around other stars, as well as the Jupiter-sized planets discovered so far.
They found that only a fraction of the planetary systems out there have giant planets at the right locations to help create an asteroid belt of the right size. In fact, it looks like the Solar System might be rare and special when it comes to perfectly-sized asteroid belts.
“Our study shows that only a tiny fraction of planetary systems observed to date seem to have giant planets in the right location to produce an asteroid belt of the appropriate size, offering the potential for life on a nearby rocky planet,” said Martin, the study’s lead author. “Our study suggests that our solar system may be rather special.”
There are three potential models for asteroid belt formation in other star systems.
A Jupiter-sized world migrates slowly inward, disrupting the asteroid belt before it can really form. All the potential asteroids are consumed or flung out into deep space. A potential Earthlike world is deprived of the chemicals (and catastrophic incentive) to evolve complex lifeforms. That’s bad
No large Jupiter-sized world forms at all, allowing the solar system to create a massive asteroid belt. Material from this enormous asteroid belt would be too punishing to Earthlike worlds for complex life to stand a chance. Also bad.
A Jupiter-sized world forms in the outer solar system, and only moves in a little, preventing an overly large asteroid belt from forming. There are still enough asteroids out there to seed an Earthlike world with chemicals and evolutionary encouragement, but not enough to set its progress back. That’s us!
To come to this conclusion, Martin and Livio created models of protoplanetary disks around various stars, and then watched what would happen with various Jupiter-sized planets. They compared their models to 90 protoplanetary disks that have been discovered so far by NASA’s Spitzer Space Telescope, and 520 giant planets found orbiting other stars.
So far, only 4% of the systems they’ve observed have the right combination of a compact asteroid belt with a Jupiter-sized planet nearby. This gives researchers a very specific configuration of asteroid belt and planetary arrangement to look for when searching for worlds that could contain complex life.
An artist’s rendering of the asteroid Apophis. Credit: ESA
What would be a way to deflect asteroid Apophis if it gets a little too close for comfort in 2029 or 2036? Pew-pew it with 5 tons of white paintballs. Not only would the multiple mini impacts bump the asteroid off course, but the white paint would cover the surface and reflect more sunlight, and over time, the bouncing of photons off its surface could create enough of a force to push the asteroid off its course.
That’s the idea of the winning entry in this year’s Move an Asteroid Technical Paper Competition, sponsored by the United Nations’ Space Generation Advisory Council. Sung Wook Paek, a graduate student in MIT’s Department of Aeronautics and Astronautics, says if timed just right, pellets full of paint powder, launched in two rounds from a spacecraft at relatively close distance, would cover the front and back of an asteroid, more than doubling its reflectivity, or albedo. The initial force from the pellets would bump an asteroid off course; over time, the sun’s photons would deflect the asteroid even more.
This video portrays how the paintball technique would work:
There have been lots of ideas put forth for possible asteroid deflection, such as using a gravity tractor to pull it off course, hitting it with a projectile or spacecraft to move it, or attaching a solar sail to change its course, to name a few.
Paek said his paintball strategy builds on a solution submitted by last year’s competition winner, who proposed deflecting an asteroid with a cloud of solid pellets. Paek came up with a similar proposal, adding paint to the pellets to take advantage of solar radiation pressure — the force exerted on objects by the sun’s photons.
In his proposal, Paek used the asteroid Apophis as a theoretical test case. This 27-gigaton rock may come close to Earth in 2029, and then again in 2036. Paek determined that five tons of paint would be required to cover the massive asteroid, which has a diameter of 450 meters (1,480 feet). He used the asteroid’s period of rotation to determine the timing of pellets, launching a first round to cover the front of the asteroid, and firing a second round once the asteroid’s backside is exposed. As the pellets hit the asteroid’s surface, they would burst apart, splattering the space rock with a fine, five-micrometer-layer of paint.
But this is not a quick-solution method, as Paek estimates that it would take up to 20 years for the cumulative effect of solar radiation pressure to successfully push the asteroid off its Earthbound trajectory. So if astronomers determine Apophis is a threat in 2029, we’re already too late. Additionally, the paintball method is not an option if estimates change for Asteroid 2012 DA14, which is predicted to pass very close to Earth on February 15, 2013, about 35,000 kilometers (21,000 miles) away.
Plus, using traditional paintballs, or traditional rockets for launching them, may not be ideal. Paek says the violent takeoff may rupture the payload. Instead, he envisions paintballs may be made in space, in ports such as the International Space Station, where a spacecraft could then pick up a couple of rounds of pellets to deliver to the asteroid.
But other substances could also be used instead of paint, such as aerosols that, when fired at an asteroid, “impart air drag on the incoming asteroid to slow it down,” Paek says. “Or you could just paint the asteroid so you can track it more easily with telescopes on Earth. So there are other uses for this method.”
Scientists have said the key to deflecting a dangerous asteroid is to find them early so that a plan can be developed. William Ailor, an asteroid specialist at Aerospace Corporation in California said that the potential for an asteroid collision is a long-term challenge for scientists and engineers.
“These types of analyses are really timely because this is a problem we’ll have basically forever,” Ailor says. “It’s nice that we’re getting young people thinking about it in detail, and I really applaud that.”
